diff --git a/ledger-tool/src/main.rs b/ledger-tool/src/main.rs
index d2c757c3a1..a61159d83b 100644
--- a/ledger-tool/src/main.rs
+++ b/ledger-tool/src/main.rs
@@ -1407,6 +1407,7 @@ fn main() {
                             .get_first_slot_in_epoch(warp_epoch);
                         let warped_bank =
                             Bank::new_from_parent(&base_bank, base_bank.collector_id(), next_epoch);
+                        warped_bank.freeze();
 
                         println!("Slot: {} => {}", base_bank.slot(), warped_bank.slot());
                         println!("Epoch: {} => {}", base_bank.epoch(), warped_bank.epoch());